Acetonitrile thermodynamic properties

The thermodynamic properties are also affected by the solvent and the composition of the reaction mixture, for example the corresponding values in acetonitrile are +1.79 V (1M HC104) and —0.53 V (1M Bu4NOH), respectively (3). 

The purpose of this study is to examine the structural features of acetonitrile-water mixtures over the whole composition range using the heats of solution and dilution of lithium perchlorate as a probe. The effect of water on thermodynamic properties such as heats of solution is also of interest. 

Putnam, W.E., McEachem, Jr., D.M., Kilpatrick, J.E. (1965) Entropy and related thermodynamic properties of acetonitrile (methyl cyanide). J. Chem. Phys. 42, 740-755. 

HP he study of the behavior of electrolytes in mixed solvents is currently arousing considerable interest because of its practical and fundamental implications (1). Among the simpler binary solvent mixtures, those where water is one component are obviously of primary importance. We have recently compared the effects of small quantities of water on the thermodynamic properties of selected 1 1 electrolytes in sulfolane, acetonitrile, propylene carbonate, and dimethylsulfoxide (DMSO). These four compounds belong to the dipolar aprotic (DPA) class of solvents that has received a great deal of attention (2) because of their wide use as media for physical separations and chemical and electrochemical reactions. We interpreted our vapor pressure, calorimetry, and NMR results in terms of preferential solvation of small cations and anions by water and obtained... 

Comelli, F. Lunelli, B. Francesconi, R. Excess thermodynamic properties for the binary system 1,3-dioxolane - acetonitrile at t = 40.deg.C J. Chem. Eng. Data 1988,33, 84-87... 

Villamanan, M. A. Van Ness, H. C. Excess thermodynamic properties of acetonitrile/water J. Chem. Eng. Data 1985,30, 445-446... 

We will see that this phenomenon is typical with other thermodynamic properties as well. It seems that the molecules of component - in this case those of acetonitrile - Teel the molecules of the other components - in this case those of acetaldehyde - as hostile. And this feeling becomes stronger, as the number of the other molecules increases. 

D. A. Palmer and B. D. Smith, Thermodynamic Excess Property Measurements for Acetonitrile-Benzene-n-Heptane System at 45 C". J. Client. Eng. Data, 17. 71-76 (1972). 

Despite the favorable properties of acetonitrile as a solvent, its use for equilibrium acidity measurements has its definite limitations. The pK range that is tolerable is limited at the high end by onset of solvent deprotonation, and at the low end by substrate autodissociation, as has been implicated for HCo(CO)4 [14a] and TpCr(CO)3H [22b]. These limitations can be overcome by the choice of a less polar solvent, e.g. 1,2-dichloroethane (DCE), dichloromethane, or THE. To make reliable, quantitative comparisons of thermodynamic data obtained in different solvents, it is necessary to link the acidity scales and electrode potential references in the different solvents. This has all too often proven to be a far from trivial task. Although, in principle, 1 1 relationship between the acidity scales in different solvents never exists, pK differences between closely related compounds are often almost constant when compared in different solvents. This is because their solvation properties are similar, because of similarities in size and charge distribution. In less... 

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